U.S. Pat. No. 3,532,510 to Zimmerman, issued Oct. 6, 1970, discloses a refrigerated product comprising a dough which surrounds and encloses a stable filling material. Typical fillings disclosed are peanut butter, cheese, meat, fruit and similar materials.
U.S. Pat. No. 2,860,053 to Avra, issued Nov. 11, 1958, discloses nut products and nut flavoring additives which are combined with a polyhydric alcohol such as sorbitol or mannitol. In the case of the nut products, whole or partial nuts such as shelled peanuts are coated with the polyhydric alcohol. This coating converts the nut surface from hygroscopic to substantially non-hygroscopic so that the nut product will not absorb moisture.
U.S. Pat. No. 3,552,980 to Cooper et al., issued Jan. 5, 1971, discloses a packaged peanut butter and jelly type product. This patent notes the problem that when sweet, aqueous spreads (e.g. jelly) are mixed with peanut butter and allowed to stand for a few days, the peanut butter becomes hard even though its moisture content has increased. This problem is solved by providing a modified sweet, aqueous spread containing 10-20% water, 10-20% of a non-aqueous edible liquid viscosity reducing agent such as glycerol, and 10-30% corn syrup solids, the remainder of the spread being water-soluble carbohydrates and naturally occurring fruit solids plus any optional ingredients. One function of the corn syrup solids is to "bind up" or hold the water present in the spread and thereby prevent its migration into the peanut butter.
U.S. Pat. No. 4,275,647 to Chambers et al., issued June 30, 1981, discloses a tubular center-filled food product having a rigid, friable baked outer shell and a core of edible filling material. The outer shell is formed from a batter containing mono and/or disaccharides, flour (10-20%), an edible fat or oil (5-15%), egg white and water. Edible fillings disclosed include confectionary cream, fruit paste, meat paste, cheese paste and the like which are sufficiently fluid to be pumpable when warm, but sufficiently stiff and firm upon cooling to be retained within the baked tubular shell.
U.S. Pat. No. 3,615,592 to Peterson, issued Oct. 26, 1971, discloses a marshmallow/peanut butter combination which reduces the migration of water from marshmallow to the peanut butter. This object is achieved by aerating the marshmallow mixture in a warm condition with a polyglycerol higher fatty acid partial ester as an emulsifier. See also U.S. Pat. No. 3,969,514 to Tiemstra, issued July 13, 1976, which discloses a nut butter/marshmallow spread combination wherein moisture transfer is lessened by lowering the difference in water activity between the two spreads and/or raising the fat content of the nut spread.